1. Field of the Invention
This invention relates to an improvement in a slide driving device for use in a metal working press.
2. Description of the Prior Art
Generally, in a metal working press, if the press operating speed is increased, that is, if the time required for one stroke of a slide for use in the metal working press is reduced, the productivity of the press may be improved. However, if the downward moving speed of the slide in the substantial press working range thereof is increased in excess of a predetermined value favorable to a material to be subjected to the press working, it has a bad effect upon the resulting articles.
In a conventional slide driving device for use in a metal working press, the downwardly moving speed of the slide in the substantial press working range thereof has not been able to be reduced relative to the press operating speed supplied from the power source thereof because an eccentric sheave adapted therein to exert upward and downward movements on the slide is rotated at a constant angular velocity. Therefore, it has not been possible to increase the operating speed of such a conventional device over a predetermined value, and thus a significant improvement in the productivity of the metal working press has not been expected.